Method for constructing, deploying, using structural tubes for space deployable applications

Abstract

Methods for constructing and / or deploying / retracting structures for space deployable applications are provided. Deployable structures may include retractable, inflatable and / or self-deploying structural tubes as part or all of the infrastructure of the system for use in space deployable applications. The structural tubes herein may be rolled and / or bent and may be configured to transition from a stored state to a deployed state. The deployed state may be an elongated state to be used as a structural support.

Description

U.S. PATENT AND TRADEMARK OFFICEMethod for Constructing, Deploying, Using Structural Tubes for Space Deployable ApplicationsBACKGROUND

[0001] Remote expeditions, including interplanetary travel will require sustainable longterm power to support remote technology. Deployable solar arrays are therefore a typical solution that can be deployed in remote locations. However, there are issues present in current deployable designs that increase deployment costs and reduce the lifespan or reliability of deploying the structures.

[0002] Several firms are developing relocatable 10-kW vertical solar arrays for initial modular power generation at the lunar south pole. These adaptable 10-kW arrays can be retracted and moved as needed to support evolving requirements for initial south pole human occupation. Their relatively small size (35 m2 of deployed area) allows them to be used individually or in combination to power loads up to a few tens of kilowatts. However, because the sun is always near the horizon at lunar polar sites, using numerous small, interconnected arrays for electrical power loads much greater than ten kilowatts can result in excessive shadowing of one array onto another as well as considerable positioning, leveling, and deployment challenges when locating them at optimally illuminated locations. Thus, second-generation lunar colonization presents a need for lightweight, relocatable 50-kW class (40-60 kW) arrays for powering habitats and laboratories, rechargeable rovers, and in situ resource utilization (ISRU) mining and processing machines, and that can deploy and retract multiple times, such as at least five times.

[0003] In the interplanetary environments and / or lunar environments, the array is preferably positioned away from the physical surface to reduce shadowing from peaks and craters of the surface. For example, general specifications may require 10 meters or more separation of the solar array from the physical, environmental surface. Given the array sizes and the required standoff, structural bases meters to tens of meters wide will be needed for stability against topple, even with adjustable leveling. Heavy anchors and deep augers will not bepractical on the moon or other interplanetary locations, especially for mobile applications.Similarly, the desire for slewing and relocation precludes the use of guy lines or other full-height stationary structural augmentation.SUMMARY

[0004] Exemplary embodiments described herein include methods for constructing and / or deploying and / or retracting structures for space deployable applications. Exemplary deployable structures may include retractable, inflatable and / or self-deploying structural tubes as part or all of the infrastructure of the system for use in space deployable applications.

[0005] Exemplary embodiments described herein include novel architecture and technology for a scalable, lightweight array concepts that can be easily deployed and retracted.DRAWINGS

[0006] FIG. 1 illustrates an exemplary deployable solar array according to embodiments of the invention in a partially deployed configuration.

[0007] FIG. 2 illustrates an exemplary deployable solar array according to embodiments of the invention in a fully deployed configuration.

[0008] FIG. 3 illustrates an exemplary component part of a structure tube that may be used in deployable space applications according to exemplary embodiments described herein.

[0009] FIG. 4 is a partial close up view of the structural tube of FIG. 3.

[0010] FIGS. 5-7 are exemplary illustrations of states of deployment and / or retraction of a structural tube according to embodiments described herein.

[0011] FIGS. 8-9 are exemplary illustrations of states of deployment and / or retraction of a structural tube according to embodiments described herein.

[0012] FIGS. 10-11 illustrate an exemplary deployable panel according to embodiments described herein in different deployment states using the structural tubes described herein.

[0013] FIGS. 12-13 illustrate an exemplary deployable panel according to embodiments described herein in different deployment states using the structural tubes described herein.

[0014] FIG. 14 illustrates an exemplary structure that may take advantage of exemplary embodiments described herein.

[0015] FIG. 15 illustrates an exemplary structure in a stored configuration according to embodiments described herein.DESCRIPTION

[0016] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. These terms are merely intended to distinguish one component from another component, and the terms do not limit the nature, sequence or order of the constituent components.

[0017] It will be further understood that the terms “comprises” and / or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. Throughout the specification, unless explicitly described to the contrary, the word “comprise” and variations such as “comprises” or “comprising” will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.

[0018] In this document, when terms such as “first” and “second” are used to modify a noun, such use is simply intended to distinguish one item from another and is not intended to require a sequential order unless specifically stated. In addition, terms of relative position such as “vertical” and “horizontal”, or “front” and “read’, when used, are intended to be relative to each other and need not be absolute and only refer to one possible position of the device associated with those terms depending on the device’s orientation.

[0019] The following detailed description illustrates by way of example, not by way of limitation, the principles of the invention. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what is presently believed to be the best mode of carrying out the invention. The drawings are diagrammatic and schematic representations of exemplary embodiments of the invention and are not limiting of the present invention nor are they necessarily drawn to scale.

[0020] Exemplary embodiments described herein include methods for constructing and / or deploying and / or retracting structures for space deployable applications. Exemplary deployable structures may include retractable, inflatable and / or self-deploying structural tubes as part or all of the infrastructure of the system for use in space deployable applications. The exemplary structural tubes include constructs that define a closed perimeter and extend along a length. The shape of the closed perimeter may change along the length or remain the same. The shape of the closed perimeter may change in design, size, etc. The structural tubes shown and described herein may be rolled and / or bent and may be configured to transition from a stored state to a deployed state. The deployed state may be an elongated state to be used as a structural support.

[0021] Exemplary embodiments described herein include novel architecture and technology for a scalable, lightweight deployable structures. An exemplary optional structure may include an array concept that can be easily deployed and retracted.

[0022] Although embodiments of the invention may be described and illustrated herein in terms of solar arrays, it should be understood that embodiments of this invention are not so limited, but are additionally applicable to solar collectors, other collectors, reflectors, antenna, solar sails, etc.

[0023] FIG. 1 illustrates an exemplary deployable solar array according to embodiments of the invention in a partially deployed configuration.

[0024] In the exemplary embodiment illustrated in FIG. 1, a deployable mast is used to extend one or more arrays. The arrays or panels may be folded or collapsed into a storedconfiguration and may straighten and / or extend into a deployed configuration. The mast may be used to extend the arrays from the stored configuration to the deployed configuration.

[0025] The vertical mast may support one, two, or more z-folded solar panels. These concepts allow for ready modularity, as the tower simply needs to be heightened in order to gain more panel area. They also are less complex kinematically, as the deployment is essentially a simple one-dimensional extension.

[0026] Traditional telescoping, extendable masts generally result in a structure that is over-engineered as it must be designed for its full deployment configuration, regardless of the needs of the individual deployment. Such structures have a finite structural limit to their height, limiting the scalability of the design as long-term power needs grow, requiring substantial reengineering. Also, susceptibility to lunar dust and other persistent contaminants drives design towards folding structures rather than telescoping or similar architectures, which can become cumbersome in packaging as the singular primary structural member (mast) grows in height. Finally, the panels, as the primary objective masses, traditionally served no structural purpose on their own, so are strictly parasitic, further decreasing the strength to weight ratio of the overall system.

[0027] As described herein in further detail, structural tubes may be incorporated into the design to add structural support to the design. For example, the array or panels that are folded may include edge tubes that are similarly folded and assist in the deployment of the structure. The folding mast may also and / or alternatively take advantage of structural tubes according to embodiments described herein. The cabling may also and / or alternatively use structural tubes according to embodiments described herein to provide additional structural support to the arrays / panels shown herein.

[0028] The solar array 100 of FIG. 1, includes an upper array arm 102 and a lower array arm 104 in which a membrane 108 may be supported to couple the solar array panels 106. A deployable mast 114 may be used to deploy or retract the array panels. As illustrated, guide cables 118 may be used to maintain a desired folding pattern along fold lines 116 of the membrane and corresponding array panels. A truss structure 112 may be used to support the array panels and may create a foldable or deployable mast.

[0029] FIG. 2 illustrates an exemplary deployable solar array according to embodiments of the invention in a fully deployed configuration.

[0030] Other designs for a deployable array may also be used and take advantage of the structural tubes described herein. For example, a tetrahedral overall architecture with collapsible structural members may be used. A basic rendering of the proposed panel array and its support structure is shown in FIG. 2. Due to the lower aspect ratio and higher static stability of the design, significantly lower loads are expected to be experienced by each structural member, so the structure becomes simpler and lighter with a lower overall material volume. Furthermore, the panel array acts as a shear web for the in-plane members of the structure, decreasing the required size and weight of the members supporting the panel array. The exemplary design can be directly scaled for larger arrays with minimal additional engineering, with fewer limitations on how large the array can be.

[0031] As illustrated, a solar array comprises two or more sections. As shown, three sections are used. The solar array, in a deployed configuration, comprises a generally triangular shape. The three sections define one perimeter side of the solar array. Adjacent sections meet together at an apex of the solar array, with a lateral side of the adjacent sections extending inward toward the middle of the solar array and all of the three sections come together in a central area of the solar array. The sections may be folded such that the sections can be collapsed together into a reduced configuration.

[0032] A significant issue arises in packaging of a triangular flat panel, often requiring irregular, complicated multi-step folding patterns with periodic separations in order to sufficiently collapse the panel dimensions along both axes planar with the panel - a requirement for easy stowage and relocation due to the size of the array. Compound folds may be used to collapse a triangular sail with uniform folds, utilizing a single folding motion for dimensional reduction along both axes. The exemplary fold pattern provides minimal collapse along the longitudinal axis, but application of multiple instances of a modified pattern allows ample collapse of the complete panel in two dimensions with a single motion.

[0033] Deployment of the panel may be performed through extending each member of the supporting structure. The rendering shown in FIG. 2 shows the panel in a partially-collapsedstate in which the panels are still partially bent. FIG. 2 is for illustration purposes to show the potential collapse of the array, but the intent is for a fully planar array. However, the required tension to stretch the panel to the fully planar state would require the major structural members to be significantly stiffer and the actuators to be significantly more powerful than is required for static structural support once the array is fully deployed. Also, stowing the panel from a fully planar state requires all folds to buckle in the appropriate direction at the same time.

[0034] Exemplary embodiments may use devices to assist in the folding of the array structure. For example, small solid-state piezoelectric actuators placed within the panel itself may be used to assist the primary actuators in deployment and stowage. Exemplary embodiments of the structural tubes shown and described herein may also be used along one, or more, or all, of the perimeter of the sections and / or the solar array to assist in the deployment and / or retraction of the array.

[0035] FIG. 3 illustrates an exemplary component part of a structure tube that may be used in deployable space applications according to exemplary embodiments described herein.

[0036] Exemplary embodiments of the structures shown and described herein include structural tubes that may be incorporated into different portions of an overall deployable structure from a collapsed configuration to a deployed configuration.

[0037] Exemplary embodiments may permit the rolling and / or folding of the structural tube for storage and unrolling and / or unfolding of the structural tube for deployment.

[0038] In an optional embodiment that may be used in any combination described herein, the structural tube may be inflated to assist in deployment.

[0039] In another optional exemplary embodiment that may be used in any combination described herein, the structural tube may comprise a remembered configuration. The remembered configuration may be in a deployed configuration to assist with deployment of the structure.

[0040] In an optional embodiment that may be used in any combination described herein, the structural tube may be self-rigidizable. Exemplary embodiments of the structural tube described herein represent novel tube geometry and method of construction.

[0041] Current designs for self-rigidizing tubes utilize a monolithic thin aluminum shell, with or without a plastic laminate layer, that is unsuitable for multiple deployment / retraction cycles due to fatigue of the aluminum as it bends and straightens. Medium-strength non-self- rigidizing tubes utilize a fabric-reinforced plastic fdm composite laminate, which allow for repeated retraction and deployment, but often must be kept inflated in order to maintain structural integrity. Conventional composite inflatable tubes have a structural load limit that is too low for certain high-load applications.

[0042] Exemplary embodiments of the structural tubes shown and described herein comprise “spring tapes,” with. The anisotropic nature of the stiffness of spring tapes, however, precludes them from use as individual structural members where rigidity under significant load is required along more than one axis.

[0043] FIG. 3 illustrates an exemplary structural tube according to embodiments described herein. As illustrated, the structural tube 300 an elastic semi-cylindrical cross section, similar to those found in metal construction industry tape measures, which are rigid when straightened, but can be rolled up and / or folded for retraction when the cross section is pressed flatincludes a plurality of tape springs 302 spaced about a circumference of the structural tube. Adjacent tape springs 302 are separated with a gap therebetween. Between adjacent tape springs 302 is a flexible material 304. As explained in greater detail herein, the flexible material 304 permits the movement of the tube so that the cross-section can change and the tube can be flattened.

[0044] FIG. 4 is a partial close up view of an exemplary structural tube such as that illustrated in FIG. 3.

[0045] As illustrated, a series of spring tapes may be bonded or laminated longitudinally into a tube, spaced radially around the centerline of the tube, resulting in a “cloverleaf’ corrugated cross section, as shown in the close up of FIG. 3. The flexibility of the laminate andthe anisotropic flexibility of the spring tapes allows a collapsible cross section that can be flattened and rolled and / or bent multiple times with less risk of material failure. The rigidity of the spring tapes and the increase in section modulus of the tube due to the corrugated cross section greatly increases the rigidity and buckling strength of the tube with minimal increase in weight or envelope dimensions.

[0046] As seen in FIG. 4, a structural tube in a deployed configuration comprises a general circular tube. The general circular tube may not have a constant radius but may deviate about an average radius defining the general circular cross section. Generally circular tubes or cross sections, as uses herein, comprises tubes in which the radius fluxuates (more and / or less) than a constant radius in a generally cyclic fashion. As shown, the plurality of spring tapes have concave longitudinal surface facing radially inward toward each other so that the center of the spring tape is radially further away from the center of the structural tube than the longitudinal edges of the spring tape.

[0047] The gaps between the spring tapes may comprise a flexible tube having a generally constant radius from the center of the structural tube when in a deployed configuration. Because the material in the gap between the tape springs is flexible, the radius or shape of the tube in the space between the spring tapes may be variable or configurable.

[0048] Exemplary embodiments of the structural tube described herein comprises a cloverleaf tube in the deployed configuration with demonstratable resistance to buckling, which can still be readily flattened and rolled (and / or folded) onto a cylindrical mandrel for stowage.

[0049] Exemplary embodiments described herein may include a length of tube comprising a cloverleaf cross section with a major diameter and a minor diameter. The exemplary tube may comprise steel spring tapes with a curve radius, held together with nonfabric-reinforced tape. In an optional embodiment, the curve radius of the spring tape may be the same as a radius of the structural tube, such that the major and minor radius of the tube is the same. In an optional embodiment, the curve radius of the spring tape may be less than the radius of the structural tube such that a major and minor radius of the tube is created.

[0050] In an exemplary embodiment, the minor radius may correspond to the radius of the flexible material between the spring tapes. In an exemplary embodiment, the flexible material may be general planar across the gap between the tape springs. Therefore, the radius generated by the flexible material may be a step wise radius more like a geometric linear-sided shape than a curved structure like a circle. However, as described herein a generally circular shape and therefore an approximate radius can still be determined based on the minor deviation created by the construction of the tube resulting in the step wise sections of the flexible portions in between the curved sections of the spring tapes.

[0051] FIGS. 5-7 are exemplary illustrations of states of deployment and / or retraction of a structural tube according to embodiments described herein. FIG. 5 illustrates an exemplary embodiment in which the structural tube is fully deployed and is generally circular in cross section (with variations about a constant cross section). FIG. 6 illustrates an exemplary embodiment in which the structural tube is flatted by deforming the flexible material between the tape springs. In an exemplary embodiment, the structural tube comprises an even number of tubes and / or comprises sufficient spacing between the spring tape with and the gaps between the spring tapes so that the structural tube may flatten at flexible material positioned on opposite sides of the structural tube. FIG. 7 illustrates an exemplary embodiment in which the tube is rolled upon itself to retain the structural tube in a stored configuration. The structural tube may be rolled upon itself and / or upon a mandrel.

[0052] Exemplary embodiments described herein offers substantial improvement in both short and long column buckling due to the local stiffness and the larger effective diameter.

[0053] FIGS. 8-9 are exemplary illustrations of states of deployment and / or retraction of a structural tube according to embodiments described herein.

[0054] Similar to FIGS. 5-6, a tube is provided in FIGS. 8-9 in which a structural tube may be fully deployed with a generally circular cross section, and / or may be flattened because of the flexible material positioned between spring tapes. FIG. 8 illustrates a tube in a deployed configuration being elongated and generally linear along its length. The tube may have a constant cross section with a variable and / or constant radius. FIG. 9 illustrates the tube in a partially stored configuration in which the tube may include one or more bends.

[0055] FIGS. 10-11 illustrate an exemplary deployable panel according to embodiments described herein in different deployment states using the structural tubes described herein. FIG.10 illustrates a series of panels in a stored configuration in which sequential panels are folded back and forth on itself to reduce a length of the array. FIG. 11 illustrates the series of panels in a partially deployed configuration in which sequential panels are extended toward a linear configuration. As illustrated, the sequential panels are still folded in an intermediate position between the stored configuration and the deployed configuration.

[0056] As illustrated, one or more edges of the panels may comprise structural tubes according to embodiments described herein. The structural tubes may be used to deploy the panels into a deployed configuration. As illustrated, deployment may be assisted with the inflation of the structural tube with an inflation source, like a liquid or gas canister in fluid and / or controllable fluid communication with an internal cavity of the structural tube.

[0057] FIGS. 12-13 illustrate an exemplary deployable panel according to embodiments described herein in different deployment states using the structural tubes described herein. FIG.12 illustrates a deployable panel in the intermediate state between stored and deployed, while FIG. 13 illustrates the deployable states in a fully deployed form. As illustrated, the deployable panel comprises segments that are placed circumferentially about a radial structure so that the deployment is tangential to a radial direction. As illustrated, an circumferential edge may comprise structural tubes according to embodiments described herein in which the tube may assist in the deployment of the panels.

[0058] FIG. 14 illustrates an exemplary structure that may take advantage of exemplary embodiments described herein. FIG. 14 illustrates an exemplary embodiment of a solar sail that may be used for propulsion of a spacecraft. Exemplary embodiments of the structural tubes may be used as portions of the structure of the solar sail such as, for example, lateral edges of a vane and / or in radial ridges of the sail to provide structural support of the structure. The structural tubes may be rolled to retract the sail and may be unrolled to deploy the sail.

[0059] FIG. 15 illustrates an exploded view of an exemplary structure according to embodiments described herein in a stored configuration. An exemplary system 140 comprises a deployable structure 146 according to embodiments described herein. The deployable structure146 may be any structure that may take advantage of the structural tubes according to embodiments described herein.

[0060] The system 140 may include a deployment system 145. The deployment system may comprise one or more canisters in order to inflate one or more of the structural tubes. In an exemplary embodiment, the structural tube(s) may comprise a closed terminal end. The structural tube(s) may be in fluid communication with the one or more canisters to supply an inflation fluid into an interior of the structural tube.

[0061] Other electronics, deployment mechanisms, or components 144 may also be packaged within the system as described herein. The system 140 may be positioned within a housing 141 for storage. The housing 141 may include an opening 142 to permit the deployable structure 146 to be positioned and / or removed therefrom The housing 141 may also include doors or other structure 143 to covering the opening. The housing 141, and / or door(s) 143 may be in any configuration to store and / or deploy the deployable structure 146.

[0062] Referring back to FIG. 1, an exemplary collapsible lunar structure may use a foldable mast.

[0063] Referring back to FIG. 2, a similar truss may be positioned along a perimeter edge of the deployable array (illustrated as the lower edge of FIG. 2). For the primary structural truss along the lower edge of the panel array, an exemplary truss is illustrated. As shown, the truss comprises a triangular cross section in which each cross-sectional batten triangle rotates 60° about the longitudinal axis of the truss to flatten against the adjacent triangles, resulting in a longitudinally-collapsing structure with an extremely small packaged footprint.

[0064] The illustrated exemplary triangular truss is statically stable in all three dimensions when fully deployed, owing to non-radially-symmetrical diagonal batten configurations. Two of the three diagonal battens are radially symmetrical with each other about the longitudinal axis of the truss, while the other is a mirror of one of the others. When deployed, the “odd” batten keeps the structure rigid and resists rotation, but when allowed to buckle, permits twisting about the longitudinal axis, shortening the distance between adjacent triangles as each section rotates relative to the next. A further advantage is that the truss remains stiffunder bending loads orthogonal to the odd batten, so if the truss is oriented so that the majority of the loads are orthogonal to the odd batten, buckling loads are minimized in the member and the hinge mechanism need not be so robust.

[0065] Exemplary embodiments described herein may use a Shape Memory Carbon Composite (SMCC) technology to incorporate a hinge into each odd batten to allow for the collapse of the member. The SMCC hinge requires no rotating or sliding parts and is thus suitable for use in the presence of lunar dust and other contaminants.

[0066] An initial or starter load may be required in order to induce buckling in the tube. In which case, a solid-state piezoelectric actuator(s) may be used in order to initiate collapse of the truss and / or the structural tubes according to embodiments described herein.

[0067] The length of each section of the truss is dependent upon the length of each side of the triangular battens - if the correct geometry is not used, the footprint of each triangle will shift away from center as it rotates. Also, collapse requires that the two rigid diagonal trusses cross in the middle, so maximum collapse yields a pack height of 3x the tube diameter. Using notional values of 36 inches per side and tube diameters of 1 inch, with a total truss length of 747 inches, 36 truss elements are required, and the total collapsed volume of the truss is 36 x 42 x 108 inches.

[0068] This volume could be reduced through optimization of the tube diameter and creative design of the hinge assemblies at each vertex to facilitate more efficient stacking of the intermediate elements. Furthermore, the constraint placed on the geometry to avoid shift of the triangles could be modified to allow some shift, then alternating directions of the diagonal members, allowing for fewer truss sections at the expense of a slight increase in collapsed footprint.

[0069] Referring back to FIG. 2, it may be desirable to elevate a solar array or other supported structure above the physical ground. For example, craters or other land surface features may cast shadows or obstruct the array; the effects of which may be overcome or minimized by elevating the array over the physical surface. However, similar to the array itself,deployment of such a stmcture(s) add complexity to the system, weight, and difficulty in deployment.

[0070] In an exemplary embodiment for use in lunar surface applications, it is desirable to achieve an elevation of 10 meters (30 feet) above the lunar physical surface for the solar array. Optionally, the support infrastructure would also and / or alternatively allow for leveling and slewing.

[0071] As illustrated in FIG. 2, three hinged legs using the structural tubes described herein may be used to support the primary structure. Exemplary embodiments may use tension lines for structural stability.

[0072] As illustrated in FIG. 2, exemplary embodiments of the support platform for elevating the array may include three, four, or more legs (three legs are illustrated). Each of the legs may include two structural tubes 202 according to embodiments described herein.

[0073] In an exemplary embodiment, each of the legs of the support platform may include a tension line 204 to provide further structural stability to the two or more tubular structures. Although one tension line 204 is shown for each leg, additional tension lines may also or alternatively be used.

[0074] The exemplary support platform may also include a base support 206 to the array. As illustrated, the bottom of the array may include the triangular (or other shaped) truss at a lower edge of the array for structural support. Extending from opposing ends of the lower edge of the solar array (directly or indirectly, such as through the truss coupled thereto), additional structural tubes according to embodiments described herein may come together to create a generally triangular support defining the base support. Each of the structural tubes of the legs may extend from adjacent or at an apex of the base support. For example, each apex of the base support may have two structural tubes extending approximately therefrom, one structural tube for a first leg and a second structural tube for another leg. The approximation to the end of a structural tube of the base support or near an apex of the base support is based on the desired stability of the structure to distribute and support the structure in the desired environment.

[0075] The array (or other supported structure), may also include a structural tube 208 extending from a back side of the array (or other supported structure) that couples the supported structure to the base support 206.

[0076] In an exemplary embodiment, each leg may include autonomous movable machines, such as, for example, mini rovers (electronically controlled wheels). For example, on the ground end of each leg may have autonomous mini-rovers that can assist in deployment of the leg tubes by moving radially outward from the central structure. The mini-rovers may move circumferentially to allow slewing of the complete structure.

[0077] In an exemplary embodiment, leveling may be accomplished with radial adjustments from the mini-rovers. In addition or alternatively thereto, leveling may also be performed or assisted by a winch / mandrel that can shorten and lengthen the tension lines.

[0078] For dust and contaminant resistance, the mini-rovers may not contain any actuators aside from those required to navigate the lunar surface, for which ample technology already exists. In an exemplary embodiment, the winches, mandrels, and / or actuators for tension line retraction and extension may be mounted to the primary array structure (or other supported structure or base support) and can therefore be elevated away from the ground and subject to far less contamination.

[0079] In an exemplary embodiment of deploying a structural support according to embodiments described herein, the front leg may be deployed and stowed via two reels that are mounted to the base support (such as the primary truss coupled to and / or on an edge of the support structure) and allowed to pivot as the leg members are rolled in and out.

[0080] In an exemplary embodiment, two rigid spars are incorporated into the primary structure to close out the lower frame of the structure and act as spindles for rolling extension and retraction of the legs. To reduce the length of the spars for stowage, a locking hinge may be placed in the center of the spar. The spar ends may be fixed to the outer comers of the triangular truss and the rear junction, and the end fittings may incorporate sealed bearings covered with sealing boots to allow the spar to spin along its longitudinal axis. A motor may be integrated intoone end of each spar and act similar to sailboat roller furler to allow extension and retraction of the tubes comprising the two aft legs by rolling the tube around the spar.

[0081] In an exemplary embodiment, large-diameter, thin-wall carbon fiber tubing is proposed for the rigid tubes to reduce weight while still allowing for a large bend radius of the structural tubes as they wrap around the spars.

[0082] The proposed sequence for deployment comprises:1. Begin expansion of the primary truss (coupled to an edge of the array or other support structure) and inflation of tube associated with the supported structure and / or base support.2. With the primary truss partially expanded, unfold spars and attach to the primary truss’s hardpoints.3. Begin extension and inflation of support tubes for rear legs, elevating the supported structure into position.4. As the primary truss reaches full deployment and rigidization, lock spar hinge.5. As the supported structural (array panel) approaches full deployment, activate piezoelectric actuators to flatten supported structural array - the primary structure is now fully erect.6. Deploy mini-rovers and attach to leg ends.7. Use mini-rovers to unfurl legs from spars and forward reels.8. When fully extended, legs are inflated and rigidized, then tension lines retract as mini-rovers move radially inward, lifting primary array structure to required height and adjusting for level.

[0083] Exemplary embodiments of the structural tubes may include self-rigidizing tubes utilizing a monolithic thin aluminum shell, with or without a plastic laminate layer.

[0084] Exemplary embodiments of the structural tubes may include medium-strength non-self-rigidizing tubes using a fabric-reinforced plastic fdm laminate, which allows for repeated retraction and deployment. This embodiment may be kept inflated in order to maintain structural integrity.

[0085] Exemplary embodiments of the structural tubes may include spring tapes with an elastic semi-cylindrical cross section. Exemplary spring tapes may be generally rigid when straightened but can be rolled up and / or bent for retraction when the cross section is pressed flat. Rigid is understood to include structures that maintain their shape under the pressures and forces generally experienced for the intended purpose for which the structure is being used. For example, a flag pole may be rigid as it does not bend when supporting a flag from the side of a house during normal environmental conditions, but which may still bend during a tornado or other catastrophic event in which the pole may be wrapped around a tree or other unlikely or non-normal use case or event.

[0086] Exemplary embodiments of the structural tubes may include a series of spring tapes bonded or laminated longitudinally into a fabric-reinforced plastic fdm laminate tube. In an exemplary embodiment, the sprint tapes may be spaced radially around the centerline of the tube, resulting in a “cloverleaf’ corrugated cross section. The flexibility of the fabric laminate and the anisotropic flexibility of the spring tapes allows a collapsible cross section that can be flattened and rolled (and / or bent) multiple times with less risk of material failure. The rigidity of the spring tapes and the increase in section modulus of the tube due to the corrugated cross section greatly increases the rigidity and buckling strength of the tube with minimal increase in weight or envelope dimensions.

[0087] In an exemplary embodiment of the structural tube, a flexible tube may be provided. The flexible tube may be any supporting structure for the structural tubes described herein. For example, the flexible tube may include any combination of a thin fdm, fabric, fabric reinforced thin fdm, polymer, rubber, and / or laminate.

[0088] In an exemplary embodiment of the structural tube, a plurality of spring tapes may be bonded or laminated onto the flexible tube so that the flexible tube fully and / or partially overlaps each of the tape springs.

[0089] In an exemplary embodiment of the structural tube, the tape springs may be on an inside surface or outside surface of the flexible tube. Alternatively, some tape springs may be on an inside surface of the flexible tube, while other tape springs may be on an outside surface of the flexible tube.

[0090] In an exemplary embodiment of the structural tube, a plurality of spring tapes may be integrated within the flexible tube.

[0091] In an exemplary embodiment of the structural tube, a plurality of spring tapes may be coupled together by a flexible material to create a tubular structure. The flexible material may overlap circumferentially with only a portion of the tape springs or with all of the tape springs. For example, the flexible material may extend between the tape springs but not fully cover or be co-extensive with the tape springs circumferentially (whether or not co-extensive longitudinally). The tape springs may therefore create a portion of the tubular circumference without the presence of the flexible material. Alternatively, the flexible material may fully overlap circumferentially with the tape springs so that the flexible material is present circumferentially with and without the tape springs. Present for the flexible material includes embodiments in which the flexible material may be a fabric material and therefore not physically present at all points because of the weave but still present in its general fabric form about the circumference of the tube.

[0092] In an exemplary embodiment, the flexible material (and / or flexible tube) may include a shape memory material. The flexible material may therefore be configured to have a remembered configuration and a deformed configuration. The flexible material may have a remembered configuration, such as in a deployed configuration in which the resulting structural tube has an elongated, generally linear longitudinal shape and a generally circular (or other desired shape) cross section. The deployed configuration may include the undulation or deviation from an average radius as described herein for the structural tube. The flexible material may alternatively have a remembered configuration in the stored configuration in which the tubular cross section is generally flattened and / or the structural tube is rolled and / or bent to create a stored configuration. The structural tube in this configuration may be fully deployed with the assistance of other component parts, such as tension cables and / or inflation mechanisms. In an exemplary embodiment, the flexible material may be deformed from the remembered configuration through application of an outside force.

[0093] Exemplary embodiments described herein may include a supported structure, such as, for example, a solar array, antenna system, collector, reflector, sail, or other structure.

[0094] The system may comprise a stored configuration and a deployed configuration.

[0095] The system may be contained within a housing in the stored configuration. The housing may be used to retain the system in the stored configuration, and / or the system may retain itself in the stored configuration. The housing, and / or its door may be used for providing an additional retention force in additional to a deformation force imposed by another component part as described herein. The additional retention force may be used for long term storage and / or provide additional environmental protection for the system while it is stored in an Earthly environment. The housing may therefore be sealed.

[0096] Exemplary embodiments of the system may include electronics for controlling portions of the system. For example, the system may include a sequencer and / or electronic may include communication systems; interface systems for coupling to other electronic system; controllers; sequencer; actuators, inflators, inflation tanks, motors, and combinations thereof. The sequencer and / or electronics may communicate with controllers, and / or permit the actuation of one or more of the system components described herein. For example, a controller may interface with the fluid injection system to inflate the structural tube as described herein. For example, a controller may interface with the release mechanism for the system for removing the deformation force and permitting the structure to transition to a deployed configuration. This may be by opening a door of the housing, firing a pyrotechnic charge to remove another failure component, by inflating the inflation envelop with a fluid to overcome a failure interface, or actuating any of the motors and / or devices described herein to extend or retract tension lines and / or deployable structures including the structural tubes as described herein, and / or any combinations thereof.

[0097] Exemplary embodiments of the system shown and described herein may include one or more deployment systems.

[0098] In an exemplary embodiment of the deployment system, the system may include an inflation fluid to inject into the tube to transition the tube from the stowed configuration to the deployed configuration, to initiate the transition to a remembered deployed state, to perturb the cross section of one or more of the tape springs to extend the tape spring, to support the structure tube during and / or after deployment, or any combination thereof.

[0099] In an exemplary embodiment of the deployment system, the terminal end and / or at select positions along the length of the support tube may include a retainer ring to return the tube to a desired configuration. For example, the retainer ring may be an elastic, rubber, or other flexible material with a remembered or low stress shape. The remembered shape may be generally circular. The structure tube may be retained in a desired stored configuration by a retaining force, but open removal of the retaining force, the retainer ring may bias the tube to a deployed configuration to initiate the deployment of the structure tube from the stored configuration to the deployed configuration.

[0100] In an exemplary embodiment, the deployment system may be configured to control a relative position of the tape springs. For example, the deployment system may comprise an attachment to the terminal ends of one or more tape springs defining the support tube. The deployment system may be configured to position the tape springs in a position to facilitate stowage by flatting out the structural tube by brining opposite tape springs toward each other and off-setting the tape springs to flatten out the tubular cross section. The deployment system may then be configured to deploy the structural tube by positioning the terminal ends of the tape spring in the general circular circumferential position of the deployed configuration.

[0101] Exemplary embodiments of a system may include one or more actuators for controlling one or more components of the system. An exemplary (optional) actuator may include a compressed gas canister and controller. The compressed gas canister may be in fluid communication with an interior of a cavity of an inflation envelope created by a support structure and / or structural tube as described herein. An exemplary (optional) actuator may include a rotatable mandrel use to roll (retract) and / or extend a structural tube from a rolled configuration (stored configuration) to a deployed configuration as described herein.

[0102] Exemplary embodiments of a system may include the antenna structure, collector structure, solar array, or other support structure.

[0103] As shown and described herein, a spring tape may be an elongate structure having an elastic semi-cylindrical cross section. The spring tape is configured to be rigid when straightened but can be rolled up and / or folded for retraction when the cross section is deformed from the semi-cylindrical shape. In the deformed shape of the stored configuration, the springtape stores strain energy from the deformation of the semi-cylindrical cross section that when released, returns the spring tape to the desired configuration. The desired configuration may be a remembered configuration in which the tape spring is generally linear in an elongated dimension and the cross section is semi-cylindrical.

[0104] Exemplary embodiments of the structural tubes shown and described herein may be used as hinges within a support structure.

[0105] As used herein, the terms "about," "substantially," or "approximately" for any numerical values, ranges, shapes, distances, relative relationships, etc. indicate a suitable dimensional tolerance that allows the part or collection of components to function for its intended purpose as described herein.

[0106] Although embodiments of this invention have been fully described with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art. Such changes and modifications are to be understood as being included within the scope of embodiments of this invention as defined by the appended claims. Specifically, exemplary components are described herein. Any combination of these components may be used in any combination. For example, any component, feature, step or part may be integrated, separated, sub-divided, removed, duplicated, added, or used in any combination and remain within the scope of the present disclosure. Embodiments are exemplary only, and provide an illustrative combination of features, but are not limited thereto.

[0107] The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMSThe invention claimed is:

1. A system, comprising: a deployable structure; one or more structural tubes, wherein each of the one or more structural tubes comprises a plurality of tape springs positioned circumferentially about the structural tube and separated by adjacent ones of the one or more structural tubes with a gap, and a flexible material coupling adjacent ones of the one or more structural tubes.

2. The system of claim 1, wherein the flexible material is bonded and / or laminated to the adjacent ones of the one or more structural tubes.

3. The system of claim 1, wherein the flexible material and the plurality of tape springs define a tubular structure.

4. The system of claim 3, wherein the tubular structure comprises a generally circular cross section in a deployed configuration with deviations in the radius of the tubular structure from an average radius.

5. The system of claim 4, wherein a radius of the tubular structure at the flexible material is generally constant and the radius of the tubular structure at the tape springs changes.

6. The system of claim 4, wherein a radius of the tape springs is different from the radius of the average radius of the tubular structure and / or a radius of the tubular structure at the flexible material.

7. The system of claim 1, wherein the flexible material comprises a flexible tube.

8. The system of claim 1, wherein the flexible material comprises a plurality of strips that extend between the plurality of tape springs.

9. The system of claim 1, wherein the one or more structural tubes comprises a stored configuration and a deployed configuration, wherein the stored configuration is rolled and / or folded.

10. The system of claim 1, wherein the deployable structure comprises a solar array, an antenna, a reflector, or a collector.

11. The system of claim 1, wherein the one or more structural tubes are configured as a support platform.

12. The system of claim 11, wherein the support platform comprises two of the two or more of the structure tubes defining a leg.

13. The system of claim 11, wherein the support platform comprises three legs and each leg comprises two structural tubes of the one or more structural tubes and a tension line.

14. The system of claim 13, wherein the support platform is configured to be deployed by extending the three legs wherein the structural tubes of the three legs are from a rolled configuration in the stored configuration to a linear configuration in the deployed configuration.

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